MCAT-PSY: Biology and Behavior

Franz Gall

developed phrenology, that function and personality was related to brain anatomy

Pierre Fluorens

performed extirpation on pigeons, studied the functions of the major sections of the brain

William James

the father of functionalism, that studied how mental processes help individuals adapt to their environments

John Dewey

involved in functionalism, believed that psychology should focus on the study of the organism as a whole

Paul Broca

examined behavioral deficits in people with brain damage

Hermann von Helmholtz

measured the speed of a nerve impulse, transitioned psychology to a natural science

Sir Charles Sherrington

inferred the existence of synapses

reflex arc

interneurons send response signals directly back to motor neurons without traveling to the brain

parasympathetic nervous system

rest and digest, conserves energy

acetycholine

sympathetic nervous system

fight or flight, expends energy in times of stress

adrenaline and noradrenaline

meninges

connective tissue that protects and anchors the brain and resorbs cerebrospinal fluid

three layers: dura mater, arachnoid mater, pia mater

cerebrospinal fluid

surrounds CNS

produced by specialized cells that line the ventricles of the brain

brainstem

most primitive region of the brain

composed of the hindbrain and midbrain

limbic system

a group of neural structures primarily associated with emotion and memory

cerebral cortex

the outer covering of the cerebral hemispheres associated with higher order functions and problem solving

rhombencephalon

develops into the hindbrain

divides into myelencephalon and metencephalon

hindbrain

controls balance, motor coordination, breathing, digestion

myelencephalon

develops into medulla oblongata

medulla oblongata

a lower brain structure that is responsible for regulating breathing, HR, BP

metencephalon

develops into pons and cerebellum

pons

contains sensory and motor pathways between the cortex and medulla

cerebellum

helps maintain posture and balance and coordinates body movements

mesencephalon

develops into the midbrain

midbrain

receives sensory and motor information from the body

involuntary reflex responses triggered by stimuli

superior colliculus

one of two prominent nuclei in the midbrain

receives visual sensory input

inferior colliculus

one of two prominent nuclei in the midbrain

receives auditory information

prosencephalon

develops into the forebrain

divides into telencephalon and diencephalon

forebrain

associated with complex perceptual, cognitive, behavioral processes

telencephalon

develops into the cerebral cortex, basal ganglia, and limbic system

diencephalon

develops into the thalamus, hypothalamus, posterior pituitary gland, and pineal gland

cortical maps

created from mapping the firing neurons from different regions in a patient’s brain as they are electrically stimulated

electroencephalogram (EEG)

detects broad patterns of neural activity based on neural recordings by electrodes placed on the scalp

regional cerebral blood flow (rCBF)

detects broad patterns of neural activity based on increased blood flow to different parts of the brain

computed tomography (CT)

multiple x-rays are taken at different angles and processed by a computer to cross-sectional slice images of the tissue

positron emission tomography (PET) scan

a radioactive sugar is injected into the body and its dispersion and uptake throughout the target tissue is imaged

magnetic resonance imaging (MRI)

uses a magnetic field to interact with H and map out H dense regions of the body

functional magnetic resonance imaging (fMRI)

uses a magnetic field to interact with H but specifically measures changes associated with blood flow

thalamus

in forebrain, relay station for all incoming sensory information except smell

hypothalamus

in forebrain, controls homeostasis and emotional experiences during high arousal states

lateral hypothalamus (LH)

the hunger center, triggers eating and drinking

ventromedial hypothalamus (VMH)

the satiety center, provides signals to stop eating

anterior hypothalamus

controls sexual behavior, sleep, and body temperature

posterior pituitary gland

site of release for ADH and oxytocin

antidiuretic hormone (ADH)

vasopressin

acts on kidneys to preserve water, reducing urine output and maintaining blood volume and pressure

oxytocin

neurotransmitter that enhances bonding, trust, and social recognition

pineal gland

secretes melatonin and receives direct signals from retina for coordination with sunlight

melatonin

hormone that regulates circadian rhythms

basal ganglia

in midbrain, coordinate muscle movement and steady posture and relay information to CNS

extrapyramidal system

gathers information about body position and carries to CNS, but does not function directly through motor neurons

Parkinson’s disease

a chronic illness associated with destruction of portions of the basal ganglia

jerky movements and uncontrolled tremors

septal nuclei

a primary pleasure center in the brain

associated with addictive behaviors

hippocampus

helps consolidate information to form long-term memories

redistributes remote memories to the cerebral cortex

fornix

a long projection that allows for communication between hippocampus and other portions of the limbic system

anterograde amnesia

a loss of memory for any new information

retrograde amnesia

a loss of memory before the traumatic event

gyri

bumps on the cortex

sulci

folds on the cortex

prefrontal cortex

in frontal lobe

supervises and directs operations of other brain regions

perception, memory, emotion, impulse control, long-term planning

association area

an area that integrates input from diverse brain regions

projection areas

an area that performs more rudimentary perceptual and motor tasks

primary motor cortex

located on the precentral gyrus (just in front of central sulcus)

initiates voluntary motor movements

projection area

motor homonculus

visual representation of the fine motor control requirements of certain sets of muscles

Broca’s area

in left hemisphere, vital for speech production

somatosensory cortex

located on the postcentral gyrus (just behind the central sulcus)

involved in somatosensory information processing

somatosensory homonculus

visual representation of the somatosensory processing requirements

striate cortex

visual cortex, how visual information is relayed

auditory cortex

primary site for sound processing, including speech and music

Wernicke’s area

associated with language reception and comprehension

contralateral communication

one side of the brain communicates with the opposite side of the body

ipsilateral communication

one side of the brain communicates with its side of the body

dominant hemisphere

usually left

language production and comprehension, logic, math,

nondominant hemisphere

usually right

intuition, creativity, music cognition, spatial processing

acetylcholine

a neurotransmitter found in CNS and PNS

CNS: linked to attention and arousal (loss in hippocampus = Alzheimer’s)

PNS: transmits nerve impulses to muscles (used in parasympathetic NS and innervating sweat glands in sympathetic NS)

catecholamines

includes epinephrine, norepinephrine, and dopamine

classified as monoamines/biogenic amines

play roles in the experience of emotions

epinephrine

adrenaline

secreted from adrenal medulla to act as hormone

norepinephrine

noradrenaline

acts at local level as neurotransmitter

low = depression, high = anxiety and mania

dopamine

plays an important role in movement and poster (mostly found in basal ganglia)

dopamine hypothesis of schizophrenia

that delusions, hallucinations, and agitation associated with schizophrenia arise from too much dopamine/an oversensitivity to dopamine in the brain

serotonin

biogenic amine neurotransmitter

regulates mood, eating, sleeping, dreaming

low = depression, high = mania

gamma-aminobutyric acid (GABA)

a neurotransmitter that produces inhibitory postsynaptic potentials (causes hyperpolarizing) and plays an important role in stabilizing neural activity

glycine

a neurotransmitter in CNS that inhibits responses by increasing chloride influx into the neuron

hyperpolarizes postsynaptic membrane

glutamate

a neurotransmitter in the CNS that’s excitatory

neuromodulators (neuropeptides)

slower and have longer effects on postsynaptic cells than neurotransmitters

endorphins

neuromodulator, natural painkillers

relatives are enkephalins

have actions similar to morphine and other opioids

hypophyseal portal system

directly connects hypothalamus and pituitary gland

anterior pituitary gland

releases hormones that regulate activities of endocrine glands

controlled by hypothalamus

adrenal glands

on top of kidneys

adrenal medulla

releases epinephrine and norepinephrine as part of sympathetic NS

adrenal cortex

produces many hormones called corticosteroids (includes cortisol)

produces sex hormones (testosterone and estrogen)

gonads

sex glands, produce sex hormones in higher concentrations (increases libido)

innate behavior

genetically programmed from evolution and is present regardless of environment or experience

learned behaviors

not based on heredity but on experience and environment

adaptive value

the extent to which a trait positively benefits a species by influencing their evolutionary fitness

monozygotic (MZ) twins

identical twins from the same zygote

dizygotic (DZ) twins

fraternal twins from two different zygotes

concordance rates

the likelihood that both twins exhibit the same trait

neurulation

occurs when the ectoderm overlying the notochord begins to furrow and form a neural groove surrounded by two neural folds

neural crest

cells at the leading edge of the neural fold

migrate throughout the body to form disparate tissues

neural tube

cells away from the leading edge of the neural fold

ultimately forms the CNS

alar plate

in neural tube, differentiates into sensory neurons